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For connecting the trickle charger, is there a difference in effectiveness of connecting the charger to the battery terminals vs plugging it into the power outlet by the passenger's legs? I've always plugged my charger into the footwell outlet and know it works - it charged my dead battery quite quickly (per my original post in this thread). But I see most connect to the battery.
For connecting the trickle charger, is there a difference in effectiveness of connecting the charger to the battery terminals vs plugging it into the power outlet by the passenger's legs? I've always plugged my charger into the footwell outlet and know it works - it charged my dead battery quite quickly (per my original post in this thread). But I see most connect to the battery.
No difference, but on some 991s, all of the interior power outlets are shut down by the computer after 15 or 20 minutes of inactivity, including the one in the footwell. All of them timed out on my 2016 base Black Edition.
No difference, but on some 991s, all of the interior power outlets are shut down by the computer after 15 or 20 minutes of inactivity, including the one in the footwell. All of them timed out on my 2016 base Black Edition.
One is fused, one isn't.
Not that anyone here is stupid enough to stuff more than 20 amps through that outlet, I hope.
For connecting the trickle charger, is there a difference in effectiveness of connecting the charger to the battery terminals vs plugging it into the power outlet by the passenger's legs? I've always plugged my charger into the footwell outlet and know it works - it charged my dead battery quite quickly (per my original post in this thread). But I see most connect to the battery.
"Effectiveness" - Not as far as I know. A trickle charger properly connected to either 12VDC outlet will recharge the battery cells. However, for me, I've tried all the internal 12V outlets in both my 981S (sold) and 991.2. Sometimes they would work, and sometimes they would time out; I'm not sure why. I ended up deciding to direct wire for a more reliable connection, but all the different options have their pros and cons.
I use a small charger (NOCO Genius1 1 Amp) because my battery is new or nearly new. I live in a warm climate, so I don't need a high charging current. The typical CTEK 4 Amp charger (or the "Porsche" rebranded one at double the price ) can put out as much as 4 to 5 Amps, or more, depending on model.
I opted to tape/zip tie my NOCO pigtail directly to the battery studs via SS M8 nuts and washers. They are a direct screw on; once you remove the alligator clips from the NOCO pigtail, the rings they use fit directly over the battery post studs.
This gives me a quick and easy connection point outside the car. I park, then fish out the pigtail from underneath the driver wiper, remove the plug cover, and insert the charging cable. I like the NOCO because it remembers the "AGM" setting from last time, useful to me if the power goes out (which it does, here in FL) since charging will resume automatically. This is one reason why I don't like the CTEK chargers which you have to click the button to select "AGM" each and every time they power up. Being direct connect, not inside, I don't have to worry about squashing the charging cable on the gasket when the door shuts.
Last edited by Rich_Jenkins; 09-09-2021 at 01:47 PM.
Not even close. These are AGM batteries and "should" have a longer lifespan than a good old standard FLA (Flooded Lead Acid) battery. By "should", I mean the battery was not abused by letting it discharge and then sit for months in that state. I got 14 and 16 years out of a factory fitted FLA battery; cars that we bought new and were therefore maintained by me.
The original battery in my 2015 991 has a build date of May 2015 and it starts like it did on day-one.
Originally Posted by james280
Should I replace it now as a preventative measure?
Only if a battery test (load test and capacity test) indicates that it is near its end-of-life. As for a capacity test, those "quick testers" that take 15 seconds do not really do a real capacity test. I have found them to be unreliable in many cases.
No difference, but on some 991s, all of the interior power outlets are shut down by the computer after 15 or 20 minutes of inactivity, including the one in the footwell.
In 6 minutes and 3 seconds each time, using my stopwatch. I had a dash cam temporarily connected to the power outlet in the glove compartment and it took that long to shut down.
For connecting the trickle charger, is there a difference in effectiveness of connecting the charger to the battery terminals vs plugging it into the power outlet by the passenger's legs? I've always plugged my charger into the footwell outlet and know it works - it charged my dead battery quite quickly (per my original post in this thread). But I see most connect to the battery.
Speaking for myself, I’m able to plug my maintainer into the “always on” outlet in the car (not the case in my previous 911), but I ran the pigtails directly to the battery as a backup for the day the battery dies with the doors locked. It’s guaranteed to never happen now.
09-08-2021, 05:09 PM
) can put out as much as 4 to 5 Amps, or more, depending on model.